“I cannot fail to acknowledge the grave scandal caused in Ireland by the abuse of young people by members of the Church charged with responsibility for their protection and education,” the Pope told political leaders and dignitaries at Dublin Castle.

“The failure of ecclesiastical authorities – bishops, religious superiors, priests and others – adequately to address these repellent crimes has rightly given rise to outrage, and remains a source of pain and shame for the Catholic community,” he said.

“I myself share those sentiments.”

The Pope veered off his script when speaking out about abuse, saying he had set out a “greater commitment to eliminating this scourge in the Church, at any cost”.

He was speaking after Irish PM Leo Varadkar said the failures of the Church, the state and wider society had created a “bitter and broken heritage for so many, leaving a legacy of pain and suffering”.

Mr Varadkar said the “heartbreaking stories” of “unspeakable crimes”, perpetrated by religious officials and then obscured to protect the institutions, was a story “all too tragically familiar” to people in Ireland.

Flowers and vestments

The Pope’s visit will end with a Mass for 500,000 people at Phoenix Park on Sunday.

Having been presented with flowers and vestments by children after his aeroplane Shepherd One touched down at Dublin Airport, Pope Francis was welcomed to the country by President Michael D Higgins at Áras an Uachtaráin (the president’s residence).

The Pope heard Mr Varadkar, a gay man, speak out against the traditional Catholic teaching on the family.

He said that the Republic of Ireland had modernised its laws, “understanding that marriages do not always work, that women should make their own decisions and that families come in many forms” – including those headed by a lone parent, same-sex parents or parents who are divorced and remarried.

On Saturday evening, the Pope will attend the Festival of Families concert in Dublin’s Croke Park stadium.

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More than 70,000 people are expected to take part, with the world-renowned tenor Andrea Bocelli, country singer Nathan Carter, and acclaimed Irish singer Daniel O’Donnell among the performers.

The pontiff will travel to County Mayo on Sunday morning for a visit to Knock Shrine, before returning to Dublin to close the World Meeting of Families at an afternoon Mass in front of an estimated 500,000 people in Phoenix Park.